A new and simplified extraoral approach for inferior alveolar nerve block: a cadaveric study and clinical case reports.

PURPOSE: Inferior alveolar nerve (IAN) and lingual nerve (LN) blocks are commonly performed using the intraoral landmark techniques. However, these methods have a risk of unanticipated nerve and arterial injury or a higher failure rate. We developed a novel extraoral approach for the IAN and LN blocks, the "inferior alveolar nerve block mandibular angle approach (IANB-MA)," using ultrasound guidance. The mechanism of action of this nerve block was examined anatomically, and its clinical feasibility was reported. METHODS: We performed the IANB-MA on four cadavers using different dye volumes (2, 4, 6 and 8 mL). The ultrasound probe was placed on the lower edge of the mandibula of each cadaver, and the needle was advanced to the mandibular inner surface. Blue acrylic paint solution was injected, and its spread was evaluated by dissection. RESULTS: Our study showed that the medial pterygoid muscle fascia was stained in all cadavers. The dye reached the LN consistently, and the IAN was stained with higher volumes (6 mL and 8 mL). The pterygomandibular space was filled with 6 mL and 8 mL of the dye. The IANB-MA successfully reduced pain in three patients with trigeminal neuralgia, tongue or jaw pain. CONCLUSIONS: The IANB-MA is a novel ultrasound-guided approach to the IAN and the LN. The clinical feasibility and effectiveness of this technique were confirmed in our patients. It may be a good alternative analgesic approach to other conventional approaches.

[The state of the bone structures of the temporomandibular joint in dental patients with unilateral terminal defects of the dentition]. / Sostoyanie kostnykh struktur visochno-nizhnechelyustnogo sustava u patsientov s odnostoronnimi kontsevymi defektami zubnykh ryadov.

OBJECTIVE: The aim of the study was to evaluate morphological changes in the bone structures of the elements of the temporomandibular joint in patients with unilateral terminal defects of the dentition. MATERIAL AND METHODS: The study involved 90 patients aged 18 to 44 years, who underwent: clinical examination of the maxillofacial region, cone-beam computed tomography with digital processing of computed tomograms in the Avantis 3D system, statistical processing of the results obtained. In the course of the study, two main samples were determined: depending on the side of the defect and on the duration of the appearance of the defect of the dentition. RESULTS: During the study of 90 computed tomograms of patients with unilateral terminal defects of the dentition and their further computer processing, the structural features of the bone elements of the temporomandibular joint were studied, the main morphometric changes of the mandibular heads were established, a comparative characteristic of morphometric parameters in the study groups was carried out. CONCLUSION: The identified structural changes in the heads of the lower jaw in patients with unilateral end defects of the dentition appear as a result of the presence of an untreated defect of the dentition for a long period of time.

Telangiectatic osteosarcoma of the mandible-A rare case report and an insight into differential diagnosis.

Telangiectatic osteosarcoma (TOS) is a rare variant of osteosarcoma that typically affects young individuals and long bones. The case under discussion was seen in the mandible of a 57-year-old female and had rapidly grown in size within a week. Microscopically, the tumour was characterised by large vascular cavities surrounded by anaplastic cells. Thin lacy tumour osteoid was observed at various foci. Abundant multinucleated osteoclastic giant cells along with areas of necrosis were also noted. The tumour cells were positive for SATB2, while negative for Cytokeratin AE1/3, CD 34. Ki-67 positivity was observed in more than 50% of tumour cells. A diagnosis of high grade telangiectatic osteosarcoma was thus made.

The usefulness of cutting guides for resection or biopsy of mandibular lesions: A technical note and case report.

The application of three dimensional (3D) printed patient specific cutting guide for biopsy of a mandibular lesion closely positioned to the mandibular canal is presented. To prevent inferior alveolar nerve damage, the cutting site of the bone window was virtually planned and then the cutting guide was 3D printed. This guide enabled intra-operative control and resulted in absence of postoperative hypo- or dysesthesia. This case demonstrates that 3D printed patient specific guides can help reduce the risk of hypoesthesia in mandibular surgery.

Meta-analysis of the survival rate and postoperative infection rate of primary and secondary implants after vascularized fibula transplantation for reconstruction of jaw defects.

OBJECTIVES: Vascularized fibula flap transplantation is the most effective and common method to repair the jaw defects. In addition, implantation is the first choice to restore dentition on the graft fibula. Implants are usually implanted at least 6 months after fibula transplantation. Primary implantation of implants during surgery can restore the dentition earlier, but whether this method can achieve the same restorative effect as secondary implantation is still uncertain. This article aims to compare the survival rate and complications between primary and secondary implantation through meta-analysis. METHODS: This meta-analysis was conducted according to PRISMA protocol and the Cochrane Handbook of Systematic Reviews of Interventions. According to the inclusion and exclusion criteria, we selected the PubMed, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), Chinese BioMedical Literature Database (CBM) according to established inclusion and exclusion criteria. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the included studies. Meta-analysis was conducted to compare the survival rate and postoperative infection rate of primary and secondary implantation. RESULTS: Seven studies were involved in our research, involving 186 patients. Five of the studies detailed implant success in 106 patients (primary implantation 50, secondary implantation 56), and four studies documented infection after implantation in 117 patients (primary implantation 52, secondary implantation 65); the survival rate of the primary implantation was 93.3%, and the incidence of postoperative infection was 17.3%. The survival rate of the secondary implantation was 93.4%, and 23.1% had postoperative infection. Meta-analysis showed that there was no significant difference in the survival rate between primary implantation and secondary implantation, OR = 0.813 (95% CI 0.383-1.725, P = 0.589 > 0.05), and there was no significant difference in the incidence of postoperative infection, OR = 0.614 (95% CI 0.239-1.581, P = 0.312 > 0.05). CONCLUSIONS: Based on the results of this study, the research found no significant difference in the survival rate or infection rates between primary and secondary implantation. After appropriate indications selection, primary implantation can be used to reconstruct the dentition with less waiting time, reduce the impact of radiotherapy, and bring a higher quality of life for patients.

The complete anatomy of the mandibular lingula: a meta-analysis with clinical implications.

BACKGROUND: The objective of this meta-analysis was to investigate the anatomical variations of the mandibular lingula (ML) and its relationship to surrounding anatomical structures. Understanding such variations is crucial to help determine the site and depth of a successful inferior alveolar nerve (IAN) anesthetic block as well as a safe area for oral and maxillofacial invasive procedures in order to minimize the risk of neurological or hematological damage to the inferior alveolar nerve. MATERIALS AND METHODS: A systematic search was conducted in which all studies were searched on the anatomy of ML. Major medical databases such as PubMed, Scopus, Embase, Web of Science, Google Scholar, Cochrane Library were searched. RESULTS: All of the results were based on a total of 4694 subjects. The overall height of the ML was found to be 8.17 mm (SE =0.22). The Triangular Type of the ML was found to be the most common one. The pooled prevalence of this variation was found to be 29.33% (LCI = 23.57% ; HCI = 35.24%). The pooled prevalence of the Nodular Type was set to be 27.99% (LCI = 22.64% ; HCI = 33.67%). CONCLUSIONS: The present meta-analysis provides clinically relevant information regarding the shape, location, and height variations of the ML. Understanding such variations of the ML is crucial when performing malocclusion corrections procedures that require the ML as a landmark, namely sagittal split ramus osteotomy, and intraoral vertical ramus osteotomy. Furthermore, effective anesthetic blocks during oral and maxillofacial procedures can be accomplished with a higher success rate if the correct site of injection is identified. The possible locations of the ML should be considered in order to determine the location of the mandibular foramen and, therefore, inferior alveolar bundle in order to prevent motor, sensory, or perfusion pathology during maxillofacial and oral procedures of the lower jaw.

Fracture treatment in atrophic mandible.

BACKGROUND: Fractures of the atrophic mandible have been historically treated in various ways, from intermaxillary fixation to internal fixation, some cases require bone grafts. Besides, the Luhr classification serves as a guide to select the type of treatment. OBJECTIVE: To show the treatment of fractures in atrophic mandible with plates and screws, and the potential indications of bone graft in this type of fractures. METHOD: We presented a serie of 17 patients with atrophic mandible treated with plates and screws, some of them no blocked system and other with locked screws. For patients in luhr classes II and III cancellous bone grafts were used, looking for best osteogenic response, harvesting for the proximal third of the tibia. RESULTS: Postoperative progress was generally uneventful. Oral intake with purees was resumed 24 hours after surgery, as well as ambulation. Fracture healing at 6 months was seen in 17 patients. One patient died before the 6-month time point as the result of a stroke. Delayed union was diagnosed 3 months after surgery in another patient, who refused secondary treatment. CONCLUSIONS: Treatment of fractures in atrophic mandibles with plates and screws is a reliable procedure. Luhr classification provide useful guidance regarding the use of bone grafts for best osteogenic response in the fracture. This treatment allows a quick restart of the feeding by mouth and movilization of the patients.

ANTECEDENTES: Las fracturas en mandíbula atrófica han sido tratadas desde con fijación intermaxilar hasta con osteosíntesis. Pueden requerir injertos óseos. La clasificación de Luhr es una guía para orientar el tratamiento. OBJETIVO: Mostrar el tratamiento de fracturas en mandíbula atrófica con placas y tornillos y las posibles indicaciones de uso de injerto óseo en este tipo de fracturas. MÉTODO: Se presenta una serie de 17 pacientes con mandíbula atrófica fracturada tratada con placas y tornillos, algunas con sistemas no bloqueados y otros bloqueados. En las de clase II and III se aplicó injerto óseo esponjoso para mejorar la capacidad osteogénica. El injerto se tomó del tercio proximal de la tibia, previa evaluación radiológica. RESULTADOS: La evolución en general fue satisfactoria. Se inició la vía oral con papillas y los pacientes deambularon a las 24 h de posoperatorio. Se observó consolidación en 17 pacientes. Hubo una defunción por enfermedad vascular cerebral antes de 6 meses. Una paciente tuvo retardo de consolidación diagnosticado al tercer mes, pero no aceptó tratamiento secundario. CONCLUSIONES: El tratamiento de las fracturas mandibulares atróficas con placa y tornillos bajo concepto de carga absorbida es un procedimiento confiable. La clasificación de Luhr es útil para orientar la utilización de injerto óseo, buscando mejorar la capacidad osteogénica en la fractura. Este tratamiento permite un pronto reinicio de la vía oral, así como la movilización de los pacientes.

A Mini-Pig Mandibular Defect Model for Evaluation of Craniomaxillofacial Bone Regeneration.

Craniomaxillofacial bone defects represent a clinical challenge in the fields of maxillofacial surgery and (implant) dentistry. Regeneration of these bone defects requires the application of bone graft materials that facilitate new bone formation in a safe, reliable, and predictive manner. In addition to autologous bone graft, several types of (synthetic) bone substitute materials have become clinically available, and still major efforts are focused on improving such bone substitute materials by optimizing their properties. Given the regulatory necessity to evaluate the performance of new bone substitute materials for craniomaxillofacial bone regeneration in a large animal model with similarity to human bone before clinical application, we here describe a mini-pig mandibular bone defect model that allows for the creation of multiple (critical-size) bone defects within the mandibular body of a single animal. As examples of bone substitute materials, we utilize both the clinically used BioOss granules and an experimental calcium phosphate cement for filling the created defects. Regarding the latter, its advantages are the injectable application within the defect site, in which the material rapidly sets, and the tailorable degradation properties via the inclusion of hydrolytically degrading polymeric particles. For both bone substitute materials, we show the suitability of the bone defect model to assess bone regeneration via histology and micro-computed tomography. Impact statement Given the regulatory necessity to evaluate the performance of new bone substitute materials for craniomaxillofacial bone regeneration in a large animal model with similarity to the human bone before clinical application, we here describe a mini-pig mandibular bone defect model that allows for the creation of multiple (critical-size) bone defects within the mandibular body of a single animal that can be used for the evaluation of the bone regenerative capacity of new bone grafting materials as well as tissue-engineered products for alveolar bone regeneration.

[Mandibular fractures in cattle - a review of 108 cases]. / Unterkieferfrakturen beim Rind ­ eine retrospektive Untersuchung von 108 Fällen.

INTRODUCTION: Mandibular fractures are among the most common fractures in cattle. The medical records of 108 cattle with a mandibular fracture, that were referred to the University of Zurich Veterinary Hospital from 2005 to 2019, were analysed to document the types of treatment, complications and long-term outcomes. Cattle, still alive at the time of retrospective analysis, underwent clinical and radiographic examinations. A fall was the single most common cause of a mandibular fracture (48,1 %), and a third of all cattle had a concomitant disease at the time of referral. Seventy-five cattle (69,4 %) had a single fracture, 26 (24,1 %) had two fractures and seven (6,5 %) had three fractures of the mandible. The molar part of the mandibular body was most commonly (40,7 %) fractured followed by the diastema (23,6 %), the pars incisiva (13,4 %), the ramus (12,1 %) and the symphysis (10,2 %) of the mandible. The majority of cattle (84/108, 77,8 %) had open fractures. Treatment was instituted in 63/108 animals (58,3 %) with 77/148 fractures. Of these fractures, 28 were treated with plate osteosynthesis, 25 with an external fixator, 8 with cerclage wire, 7 using mixed techniques, 4 with fragment excision, 4 underwent conservative treatment and one a mucosal suture. In total, 45/108 animals (41,7 %) were culled because of multiple fractures, concomitant diseases and because of economic reasons. Complications occurred in 34 (54,0 %) treated cattle; 22 had abnormal wound healing of which 18 developed osteomyelitis complicated by a sequestrum (14). Of the treated 63 cattle, 56 (88,9 %) were discharged. The mean postoperative productive life was 46 ± 29,2 months for animals that were deceased at the time of the study. Thirteen of the cattle with a sequestrum remained in the herd for 15 to 92 months (mean, 47 months) and one for 2 months. The life expectancy after treatment did not differ significantly from that of the Brown Swiss and Swiss Holstein dairy cattle populations, where the cattle of this study mainly came from. Eleven cattle were available for long-term follow-up; all had a good general health status but nine had dental abnormalities including missing teeth, steps or enamel points, which did not noticeably affect the body condition of the animals. Surgical treatment of selected mandibular fractures had a favourable prognosis (52/63 healed, 82,5 %) in cattle.

INTRODUCTION: Les fractures mandibulaires font partie des fractures les plus fréquentes chez les bovins. Les dossiers médicaux de 108 bovins présentant une fracture mandibulaire, référés à l'hôpital vétérinaire de l'Université de Zurich entre 2005 et 2019, ont été analysés afin de documenter les types de traitement, les complications et les résultats à long terme. Les bovins, encore vivants au moment de l'analyse rétrospective, ont subi des examens cliniques et radiographiques. Une chute était la cause la plus fréquente d'une fracture mandibulaire (48,1 %), et un tiers des bovins présentaient une maladie concomitante au moment de la consultation. Septante-cinq bovins (69,4 %) avaient une seule fracture, 26 (24,1 %) avaient deux fractures et sept (6,5 %) avaient trois fractures de la mandibule. La partie molaire du corps mandibulaire était le plus souvent (40,7 %) fracturée, suivie du diastème (23,6 %), de la pars incisiva (13,4 %), du ramus (12,1 %) et de la symphyse (10,2 %) de la mandibule. La majorité des bovins (84/108, 77,8 %) présentaient des fractures ouvertes. Un traitement a été institué chez 63/108 animaux (58,3 %) avec 77/148 fractures. Parmi ces fractures, 28 ont été traitées par une ostéosynthèse par plaque, 25 par un fixateur externe, 8 par cerclage, 7 par des techniques mixtes, 4 par une excision du fragment, 4 par un traitement conservateur et une par une suture muqueuse. Au total, 45/108 animaux (41,7 %) ont été abattus en raison de fractures multiples, de maladies concomitantes et pour des raisons économiques. Des complications sont survenues chez 34 (54,0 %) des bovins traités ; 22 ont présenté une cicatrisation anormale dont 18 ont développé une ostéomyélite compliquée par un séquestre (14). Sur les 63 bovins traités, 56 (88,9 %) sont sortis de clinique. La vie productive postopératoire moyenne était de 46 ± 29,2 mois pour les animaux qui étaient décédés au moment de l'étude. Treize des bovins avec un séquestre sont restés dans le troupeau pendant 15 à 92 mois (moyenne, 47 mois) et un pendant 2 mois. L'espérance de vie après traitement ne différait pas significativement de celle des populations de vaches laitières Brown Swiss et Swiss Holstein d'où provenaient principalement les bovins de cette étude. Onze bovins étaient disponibles pour un suivi à long terme ; tous avaient un bon état de santé général mais neuf présentaient des anomalies dentaires, notamment des dents manquantes, des différences de niveau de la table dentaire ou des pointes d'émail, ce qui n'a pas affecté de manière notable l'état corporel des animaux. Le traitement chirurgical de certaines fractures mandibulaires a donc eu un pronostic favorable (52/63 guéries, 82,5 %) chez les bovins.

Evaluation of deformation in the buccal lamellar bone with finite element analysis in alveolar ridge-splitting/expansion technique.

PURPOSE: The aim of this study was to investigate deformation and stress distribution in the buccal lamellar bone via finite element analysis (FEA) in the application of alveolar ridge-splitting/expansion technique (ARST) in atrophic maxilla and mandible. MATERIAL AND METHOD: Three-dimensional (3D) solid models of maxilla and mandible were formed using computer software, with an alveolar ridge thickness of 4 mm in the right first molar region. In both models, one horizontal and two releasing vertical osteotomies were made in the atrophic region. Vertical forces varying from 50 N to 1000 N were continuously applied on the midpoint of the horizontal osteotomy and then the axial and total deformation and von Mises stress distribution in the buccal lamellar bone was assessed by FEA. RESULTS: The degrees of axial deformation and total deformation and the maximum von Mises stress value under a 50 N force were 0.22 mm, 0.23 mm, and 4.52 MPa in the maxillary buccal lamellar bone and were 0.04 mm, 0.06 mm, and 5.90 MPa in the mandibular buccal lamellar bone, respectively. Similarly, under a 1000 N force, the values were 4.44 mm, 4.75 mm, and 90.49 MPa in the maxillary buccal lamellar bone and were 0.96 mm, 1.1 mm, and 118.02 MPa in the mandibular buccal lamellar bone, respectively. CONCLUSION: These findings implicate that the ARST used for implant placement or alveolar augmentation can be achieved with the application of lower amounts of force in the maxilla compared to the mandible. It was also revealed that in ARST, the maximum von Mises stress value was lower in the maxillary buccal lamellar bone than in the mandibular buccal lamellar bone. Based on these findings, we consider that the administration of ARST could be biomechanically more stable in the maxilla than in the mandible.

Accuracy of Guided Implant Surgery in the Edentulous Jaw Using Desktop 3D-Printed Mucosal Supported Guides.

PURPOSE: The aim of this in vitro study is to evaluate the accuracy of implant position using mucosal supported surgical guides, produced by a desktop 3D printer. METHODS: Ninety implants (Bone Level Roxolid, 4.1 mm × 10 mm, Straumann, Villerat, Switzerland) were placed in fifteen mandibular casts (Bonemodels, Castellón de la Plana, Spain). A mucosa-supported guide was designed and printed for each of the fifteen casts. After placement of the implants, the location was assessed by scanning the cast and scan bodies with an intra-oral scanner (Primescan®, Dentsply Sirona, York, PA, USA). Two comparisons were performed: one with the mucosa as a reference, and one where only the implants were aligned. Angular, coronal and apical deviations were measured. RESULTS: The mean implant angular deviation for tissue and implant alignment were 3.25° (SD 1.69°) and 2.39° (SD 1.42°) respectively, the coronal deviation 0.82 mm (SD 0.43 mm) and 0.45 mm (SD 0.31 mm) and the apical deviation 0.99 mm (SD 0.45 mm) and 0.71 mm (SD 0.43 mm). All three variables were significantly different between the tissue and implant alignment (p < 0.001). CONCLUSION: Based on the results of this study, we conclude that guided implant surgery using desktop 3D printed mucosa-supported guides has a clinically acceptable level of accuracy. The resilience of the mucosa has a negative effect on the guide stability and increases the deviation in implant position.

Impact of skin invasion on long-term survival outcomes in gingivobuccal complex carcinoma.

INTRODUCTION: Gingivo-buccal complex cancers (GBCC) have an aggressive clinical course in the presence of skin and bone involvement. OBJECTIVE: This study intends to analyze the clinico-pathological factors affecting local control and survival outcomes in GBCC. METHODS: This is a retrospective study conducted on 125 GBCC cases from January 2011 to April 2016. RESULT: Univariate analysis revealed lymphovascular invasion (LVI) and skin involvement as predictors of poor overall survival (OS) and disease- free survival (DFS). Multivariate analysis showed skin involvement and LVI to be independent prognostic factors towards poor OS. Corresponding results in case of DFS showed skin involvement to be the single most important prognostic factor. With a median follow up of 24 months, the median survival of patients with skin involvement, skin and mandible invasion and isolated mandible invasion, respectively, were 18 months, 12 months and 22 months. CONCLUSION: GBCC with skin involvement portends poor outcome in terms of survival. In the presence of skin invasion, treatment entails liberal soft tissue and bone margin followed by adjuvant treatment.

Evaluation of trabecular pattern of mandible using fractal dimension, bone area fraction, and gray scale value: comparison of cone-beam computed tomography and panoramic radiography.

OBJECTIVE: This study was performed to compare the fractal dimension (FD), bone area fraction (BAF), and gray scale value (GSV) on digital panoramic radiography (DPR) and cross-sectional cone-beam computed tomography (CBCT) using image analysis and to determine whether a relationship exists among parameters associated with bone quality. METHODS: Thirty edentulous human hemimandibles were scanned by DPR and CBCT. Ninety regions of interest (ROIs) were evaluated on DPR and CBCT images to calculate the FD and BAF. The GSV of the ROI on CBCT was also calculated. RESULTS: Statistically significant differences were observed in the FD values of the ROIs between DPR and CBCT (p = 0.002) and in the BAF values of ROIs between DPR and CBCT (p = 0.017). The Spearman's correlation test revealed a statistically significant high correlation between the FD and BAF values of the ROIs on DPR and between the FD and BAF values of the ROIs on CBCT (p < 0.01). No significant correlations were observed between the GSVs of ROIs on CBCT and the FD values of ROIs on DPR, the BAF values of ROIs on DPR, the FD values of ROIs on CBCT, and the BAF values of ROIs on CBCT (p > 0.05). CONCLUSIONS: The GSV did not support the FD and BAF. Additionally, DPR and CBCT did not have similar image quality for assessing the FD, BAF, and GSV. In evaluating the trabecular structure, the use of panoramic radiographs should be continued because the image resolution of CBCT is lower and its generalized dose is higher than that of panoramic radiography. These results may serve as a reference for clinical practitioners using dental CBCT to analyze the trabecular structures of alveolar bones.

Mandibular assessment of panoramic radiographs for sex identification / Análise do dimorfismo sexual através de índices radiomorfométricos em radiografias panorâmicas

ABSTRACT Sex determination plays a crucial role in the post-mortem identification of human remains. One effective approach for obtaining sex-related data is to use measurements of anatomical structures such as the mandible. This study aimed to evaluate the potential of mandibular radiomorphometric indices from panoramic radiographs (PRs) for the identification of sexual dimorphism. The study sample included 300 PRs of individuals aged 51 to 80 years from the northeastern region of Brazil. Four linear measures and three numerical indices were analyzed with Inkscape® version 1.0.1 for Windows by two blinded evaluators. After statistical analysis, the results showed that the linear measurements obtained from PRs are a reliable method for sex identification. However, the calculated indices of these measurements exhibited lower efficacy for the same purpose. Therefore, PRs proved to be a valuable method for sexual identification through mandibular assessment.

RESUMO A determinação do sexo é um dado importante para a identificação post-mortem de um indivíduo ou de restos mortais humanos. Uma maneira de adquirir dados quanto ao sexo é utilizar mensurações de estruturas como a mandíbula. O objetivo principal deste estudo é avaliar a utilização de índices radiomorfométricos de mandíbulas para a identificação de dimorfismo sexual, através de radiografias panorâmicas. O estudo foi realizado em exames radiográficos panorâmicos de 300 indivíduos entre 51 e 80 anos, residentes do Nordeste brasileiro. Foram analisadas quatro medidas lineares e três índices numéricos no software Inkscape® versão 1.0.1 para Windows, por dois avaliadores cegos. Após análise estatística, os resultados demostraram que as medidas lineares obtidas se configuram como um método seguro para a identificação sexual. Entretanto, os índices obtidos através destas medidas demostraram menor eficiência para o mesmo fim. Logo, as radiografias panorâmicas podem ser utilizadas como método eficaz para a obtenção da caracterização sexual através da mandíbula.

Osteomielitis crónica mandibular. Informe de dos casos clínicos / Chronic mandibular osteomyelitis. A report of two clinical cases

Objetivo: Presentar dos casos clínicos inusuales de osteomielitis crónica en mandíbula, su resolución quirúrgica y destacar los aspectos clínicos, radiológicos e histológicos más relevantes. Casos clínicos: Se reportaron dos casos clínicos de pacientes con osteomielitis crónica en mandíbula que acudieron al Servicio de Odontología del Hospital Interzonal General de Agudos "Eva Perón". El primero fue un raro caso de osteomielitis ubicada de forma aislada en el cóndilo mandibular izquierdo. El tratamiento consistió en la resección quirúrgica del cóndilo mandibular afectado, seguido de terapia antibiótica a largo plazo. El segundo caso clínico se trató de un paciente con pericoronaritis asociado a un tercer molar inferior impactado. El tratamiento se basó en el desbridamiento quirúrgico más la colocación de drenaje, seguido de terapia antibiótica. En ambos pacientes el diagnóstico de osteomielitis se confirmó mediante el estudio histológico de las muestras quirúrgicas, y tras seguimiento de 24 y 12 meses para el caso 1 y 2 respectivamente, no se han reportado recurrencias de la patología.(AU)

Aim: To present two unusual cases of chronic mandibular osteomyelitis, its surgical resolution and highlight the most relevant clinical, radiological and histological aspects. Clinical cases: Two clinical cases of patients with chronic mandibular osteomyelitis who attended the Dentistry Service of the "Eva Perón" Interzonal General Acute Hospital were reported. The first was a rare case of osteomyelitis located isolated in the left mandibular condyle. Treatment consisted of surgical resection of the affected mandibular condyle, followed by long-term antibiotic therapy. The second clinical case was a patient with pericoronitis associated with an impacted lower third molar. Treatment was based on surgical debridement and drain placement, followed by antibiotic therapy. In both patients the diagnosis of osteomyelitis was confirmed by histological study of the surgical samples, and after follow-up of 24 and 12 months for cases 1 and 2 respectively, no recurrences of the pathology have been reported.(AU)

Fibular free flap in mandible reconstruction, a long-term follow-up.

INTRODUCTION: Fibula free-flap mandible reconstruction is the gold standard in mandibulectomized patients due to bone or oral cavity tumors. Long term follow-up and complications of this procedure are barely reported. OBJECTIVE: To know long term outcomes of patients with fibula free-flap. METHOD: Clinical evaluation of patients with fibula free-flap mandible reconstruction, 10 years after procedure. Patients intervened from 1996 to 2006 were included, clinically assessing: oral functionality, habitual dietary intake, complications and aesthetic satisfaction. RESULTS: 87 patients were included; 70 of them with bone tumors and 17 with oral carcinomas. Were successful 73 flaps, and 14 got total or partial loss, so, they were excluded. In all cases dietary regimen was similar to their original one before resection; even when in average, 3 years were necessary to get this normal intake. Any of them required major re-operation during the follow-up period and there was no late loss of the flap either. Functionality was considered normal in 100% of the cases and 80% considered themselves as aesthetically satisfied. CONCLUSIONS: Fibula free-flap offers a secure alternative for long term mandibular reconstruction.

INTRODUCCIÓN: La reconstrucción mandibular con colgajo libre de peroné es el procedimiento estándar en pacientes operados de mandibulectomía por tumores óseos o de la cavidad bucal. El seguimiento a largo plazo y las complicaciones de este procedimiento son poco reportados. OBJETIVO: Conocer la evolución a largo plazo de pacientes con colgajo libre de peroné. MÉTODO: Evaluación clínica de pacientes con colgajo libre de peroné para reconstrucción mandibular 10 años después de la intervención. Se incluyeron operados entre 1996 y 2006. Se evaluaron clínicamente la funcionalidad oral, la integración del paciente a la dieta habitual, las complicaciones y la satisfacción estética. RESULTADOS: Se intervinieron 87 pacientes: 70 por tumores óseos y 17 por carcinomas de la cavidad oral. Fueron exitosos 73 colgajos, y 14 tuvieron pérdida parcial o total y fueron excluidos. En todos los casos, el régimen alimentario fue similar al que tenían antes de la resección; la media para lograr la alimentación normal fue de 3 años. Ninguno requirió reoperación mayor durante el seguimiento. No hubo pérdida tardía del colgajo y la funcionalidad se consideró normal en el 100%. El 80% se consideraron estéticamente satisfechos. CONCLUSIONES: El colgajo libre de peroné ofrece una alternativa segura para la reconstrucción mandibular a largo plazo.

Examining the Impact of Acute Binge Alcohol Consumption on Trabecular Morphometry and Tensile Strength in Adolescent Sprague Dawley Rat Mandibles / Análisis del Impacto del Consumo Excesivo de Alcohol en la Morfometría Trabecular y la Resistencia a la Tracción en Mandíbulas de Ratas Adolescentes Sprague Dawley

SUMMARY: Underage drinking has become a major public concern having a negative impact on the growth and development of the skeleton. Peak bone mass is attained during adolescence hence the aim of the study was to investigate the effect of acute binge alcohol consumption on trabecular morphometry and tensile strength of the adolescent mandible in the Sprague Dawley (SD) rat. The study comprised of 24 SD rats, aged 7 weeks, placed into either the alcohol-exposed [n=12 (6 males and 6 female)] or pair-fed control group [n=12 (6 male and 6 female)]. The treatment of the groups was as follows; the alcohol exposed group and the pair-fed control were administered a single daily dose of 3 g/kg of 20 % alcohol 3 days a week (alternate days) for 7 days and a caloric equivalent dose of maltose dextrin via oral gavage, respectively. The animals were terminated on day 7 via pentobarbital injection. The mandibles were harvested and scanned using a Nikon XTH 255L 3D-microCT scanner (Nikon Metrology, Leuven, Belgium), and biomechanical tests were done using a Shimadzu universal tensile strength testing machine (China). Following scanning and reconstruction, the trabecular morphometry was assessed using Volume Graphics Studio® software. A 3-point bending test was used to evaluate the tensile strength of the bone. Findings from our study showed changes in some trabecular parameters in the female alcohol-exposed group, while the male groups remained unaffected. No changes in tensile strength were seen when comparing male pair-fed control and alcohol-exposed groups and when comparing female pair-fed control and alcohol-exposed groups. Trabecular and tensile strength differences were observed between the sexes when comparing male pair-fed control and alcohol-exposed groups to female pair-fed control and alcohol-exposed groups. These findings do suggest that acute binge alcohol consumption has detrimental effects on the bone micro-architecture in female alcohol-exposed rats and that differences are seen between the sexes.

El consumo de alcohol entre menores de edad se ha convertido en una importante preocupación pública que tiene un impacto negativo en el crecimiento y desarrollo del esqueleto. La masa ósea máxima se alcanza durante la adolescencia, por lo que el objetivo del estudio fue investigar el efecto del consumo excesivo de alcohol en forma aguda sobre la morfometría trabecular y la resistencia a la tracción de la mandíbula en ratas adolescente Sprague Dawley (SD). El estudio estuvo compuesto por 24 ratas, de 7 semanas de edad, colocadas en el grupo control expuesto al alcohol [n=12 (6 machos y 6 hembras)] y alimentado en parejas [n=12 (6 machos y 6 hembras)]. El tratamiento de los grupos fue el siguiente; al grupo expuesto al alcohol y al control alimentado en parejas se les administró una dosis única diaria de 3 g/kg de alcohol al 20 % 3 días a la semana (días alternos) durante 7 días y una dosis equivalente calórica de maltosa dextrina mediante sonda oral, respectivamente. Los animales fueron sacrificados el día 7 mediante inyección de pentobarbital. Las mandíbulas se recolectaron y se escanearon utilizando un escáner 3D-microCT Nikon XTH 255L (Nikon Metrology, Lovaina, Bélgica), y las pruebas biomecánicas se realizaron utilizando una máquina de prueba de resistencia a la tracción universal Shimadzu (China). Después del escaneo y la reconstrucción, la morfometría trabecular se evaluó utilizando el software Volume Graphics Studio®. Se utilizó una prueba de flexión de 3 puntos para evaluar la resistencia a la tracción del hueso. Los hallazgos de nuestro estudio mostraron cambios en algunos parámetros trabeculares en el grupo de hembras expuestas al alcohol, mientras que los grupos de machos no se vieron afectados. No se observaron cambios en la resistencia a la tracción al comparar los grupos control de machos alimentados en parejas y los grupos expuestos al alcohol y al comparar los grupos control de las hembras alimentadas en parejas y los grupos expuestos al alcohol. Se observaron diferencias trabeculares y de resistencia a la tracción entre los sexos al comparar los grupos control de los machos alimentados en parejas y expuestos al alcohol con los grupos de control de hembras alimentadas en parejas y expuestas al alcohol. Estos hallazgos sugieren que el consumo excesivo de alcohol tiene efectos perjudiciales sobre la microarquitectura ósea en ratas hembras expuestas al alcohol y que se observan diferencias entre los sexos.

Periodontal status and mandibular biomechanics in rats subjected to hyposalivation and periodontitis / Estudio del estado periodontal y la biomecánica mandibular en ratas sometidas a hiposalivación y periodontitis

ABSTRACT Xerostomia emerges as a consequence of salivary gland hypofunction, and seriously compromises the integrity of hard and soft oral tissues, whileperiodontitis is an infectious disease characterized by biofilm accumulation, inflammation and alveolar bone resorption. Aim The aim this study was to compare the deleterious effects caused by experimental hyposalivation, periodontitis, and the combination of both on periodontal tissues and mandibular biomechanics in rats. Materials and Method Hyposalivation (group H) was induced through bilateral submandibulectomy. Periodontitis (group EP) was induced by injecting LPS (1 mg/ml) into the gingiva of the first lower molars. A third group was subjected to both conditions (group H+EP). Alveolar bone loss was evaluated by micro-computed tomography and histomorphometric analysis, and gingival inflammatory mediators were assessed by specific techniques. Biomechanical properties were evaluated in mandible. Results Alveolar bone loss increased similarly in groups H, EP and H+EP compared to control. Metalloproteinase (MMP2 and MMP9) activity was similar in H and control, but higher in groups EP and H+EP (MMP2: C 9644+2214, EP 34441+3336, H 5818+1532, H+EP 42673+3184; MMP9: C 5792+961, EP 14807+861, H 9295+520, H+EP 4838+1531). The rest of the inflammatory mediators evaluated increased in groups H, EP and H+EP to a greater or lesser extent with respect to the control, although in most cases, they were higher in groups EP and H+EP than in group H. The biomechanical properties of the mandible increased in group H compared to the other three groups. Conclusions Both hyposalivation and periodontitis cause periodontal damage, but hyposalivation also produces biomechanical alterations, causing more extensive deleterious effects than periodontitis.

RESUMEN La xerostomía surge como consecuencia de la hipofunción de las glándulas salivales y compromete seriamente la integridad de los tejidos orales duros y blandos, mientras que la periodontitis es una enfermedad infecciosa caracterizada por la acumulación de biofilm, inflamación y reabsorción ósea alveolar. Objetivo El objetivo del presente estudio fue comparar los efectos deletéreos causados por la hiposalivación y la periodontitis experimental, y la combinación de ambas sobre los tejidos periodontales y la biomecánica mandibular en ratas. Materiales y Método La hiposalivación (H) se indujo mediante una submandibulectomía bilateral. Por otra parte, la periodontitis (PE) se indujo mediante la inyección de LPS (1 mg/ml) en la encía de los primeros molares inferiores. Otro grupo se sometió a ambas condiciones (H+PE). La pérdida ósea alveolar se evaluó mediante tomografia microcomputarizada y análisis histomorfométrico, mientras que los mediadores inflamatorios gingivales fueron determinados mediante técnicas específicas. Se evaluaron las propiedades biomecánicas en la mandíbula. Resultados La hiposalivación aumentó la pérdida ósea alveolar en comparación con el control de forma similar a la PE y H+PE. La actividad de las metaloproteinasas (MMP2 y MMP9) fue similar en los grupos H y control, pero resultó mayor en los grupos PE y H+PE (MMP2: C 9644+2214, PE 34441+3336, H 5818+1532, H+PE 42673+3184; MMP9: C 5792+961, PE 14807+861, H 9295+520, H+PE 24838+1531). El resto de los mediadores inflamatorios evaluados aumentaron en mayor o menor medida en los grupos H, PE y H+PE respecto al control, aunque en la mayoría de los casos fueron superiores en los grupos PE y H+PE respecto al grupo H. Sin embargo, las propiedades biomecánicas de la mandíbula aumentaron en el grupo H con respecto a los otros grupos. Conclusiones Tanto la hiposalivación como la periodontitis causan daño periodontal, pero la hiposalivación también produce alteraciones biomecánicas, provocando efectos deletéreos más extensos que la periodontitis.

Implantes curtos e ultracurtos sobre carga imediata em estruturas ósseas edêntulas e atróficas - uma revisão de literatura

Planejar uma reabilitação protética nos casos de edentulismo em estruturas ósseas atróficas envolve uma alta e extensa complexidade. Os implantes-suportados precisam de uma espessura óssea que acomode a fixação do implante funcionalmente e, nos casos de atrofia óssea, reabilitações com implantes convencionais (10mm) envolvem técnicas cirúrgicas de aumento do rebordo, que são mais invasivas e apresentam maiores riscos. Atualmente, a literatura apresenta os implantes curtos (<10mm) e ultracurtos (4mm) como uma alternativa mais segura e econômica, que tem mostrado eficiência e um bom prognóstico. O objetivo deste estudo foi avaliar as taxas de sobrevivência de próteses totais sobre implantes curtos/ultracurtos com carga imediata em estruturas ósseas atróficas. Na maioria dos casos, o carregamento imediato tem sido um pré -requisito para os pacientes e os resultados têm sido promissores. O tratamento de superfície do implante atrelado a um minucioso planejamento da prótese, viabilizam esta condição. Entretanto, o que determina o sucesso clínico é a estabilidade primária, a resposta biológica óssea e o número de implantes a serem instalados.

Quantitative structural analysis of trabecular alveolar bone in the mandible by multidetector computed tomography: differences according to tooth presence and type. / Análisis estructural cuantitativo del hueso alveolar trabecular de la mandíbula en tomografía computarizada multidetector: diferencias por tipo y estado dentario.

BACKGROUND AND OBJECTIVE: There is a lack of quantitative measures of the quality of alveolar trabecular bone, an important factor in implantology. This study aimed to develop a method of objectively assessing the quality of trabecular bone by means of image processing and structural analysis of multidetector computed tomography images and to establish differences between tooth types and tooth presence/absence. MATERIALS AND METHODS: We analyzed 20 patients who underwent multidetector computed tomography to evaluate mandibular bone and tooth positioning. Image analysis included automatic segmentation of the mandible, obtainment of sections perpendicular to the dental arch, and structural analysis of the trabecular bone in each section. We calculated the ratio between the volume of bone and the total volume of the section, the thickness, the trabecular number, and the mean attenuation in Hounsfield units. We analyzed the differences among different tooth types (incisors, canines, premolars, and molars) and between present and absent teeth. RESULTS: We found statistically significant differences between different tooth types and between sections in which teeth were present or absent. Incisors had a greater ratio of trabecular bone; the ratio of trabecular bone progressively decreased from the incisors to the canines, premolars, and molars. The ratio of trabecular bone was greater in sections in which teeth were absent than in those in which teeth were present. CONCLUSIONS: The method allows to quantify the structural properties of alveolar bone from multidetector computed tomography images. Our results provide an objective picture of the bone substrate that can be useful for planning and following up dental implant procedures.